Corrupt icons


UNIX - Live Free or Die
I've tried a searching for this but haven't found anything, if it's a known prob or a no-brainer, sorry.

Occasionally I get corrupt icons, over time the corruption will change, restarting Finder cures it, but I'd like to know why it happens, I've included a screenshot to show what I mean.

Running Mac mini 512MB, with Panther 10.3.9

Maybe OS X tries to tell you not to put files on the root of the primary volume? ;) (j/k, I truly hope that isn't the problem...)